(1. 玉林師范學(xué)院 物理科學(xué)與工程技術(shù)學(xué)院，玉林 537000；
2. 廣西大學(xué) 物理科學(xué)與工程技術(shù)學(xué)院，南寧 530004；
3. 廣西大學(xué) 廣西有色金屬及特色材料加工重點實驗室，南寧 530004)
摘 要: 基于定向退火條件下的移動熱區(qū)模型，采用相場法研究定向退火條件下熱區(qū)寬度對多晶材料中柱狀晶形成及連續(xù)擴(kuò)展的影響。模擬結(jié)果表明：增加熱區(qū)寬度有利于形成柱狀晶結(jié)構(gòu)，且所得柱狀晶的長寬比隨著熱區(qū)寬度的增加而增大；當(dāng)熱區(qū)移動速率一定時，柱狀晶連續(xù)擴(kuò)展所需臨界熱區(qū)寬度小于形成柱狀晶所需臨界熱區(qū)寬度；當(dāng)熱區(qū)寬度大于初始晶粒直徑的1.5倍時，熱區(qū)寬度對柱狀晶連續(xù)擴(kuò)展的熱區(qū)移動臨界速率的影響很小。
關(guān)鍵字: 定向退火；晶界遷移率；柱狀晶；相場法
（1. College of Physics Science and Engineering, Yulin Normal University, Yulin 537000, China;
2. College of Physics Science and Engineering, Guangxi University, Nanning 530004, China;
3. Guangxi Key Laboratory of Nonferrous Metals and Special Materials Processing, Guangxi University, Nanning 530004, China）
Abstract:Based on the moving hot zone model under directional annealing, the effects of the hot zone width on the formation and continuous propagation of columnar grain structure during directional annealing in polycrystalline materials were studied by phase field method. The simulation results show that increasing hot zone width is beneficial to the formation of columnar grain structure, and the aspect ratio of the columnar grain increases with increasing the hot zone width. For a given zone speed, the critical hot zone width for propagation of columnar grain is smaller than that for its formation. When the hot zone width is 1.5 times greater than the initial grain diameter, the effect of the hot zone width on critical hot zone speed necessary for the continuous propagation of columnar grain structure is rarely small.
Key words: directional annealing; grain boundary mobility; columnar grain; phase field method
